JP7529640B2 - Packaging Bag - Google Patents

Description

The present invention relates to a packaging bag.

2. Description of the Related Art Packaging bags have been used in the past, in which the opening of the bag can be opened and closed using a zipper portion, and when the zipper portion is closed, the bag maintains airtightness and allows the contents, such as food and beverages, to be stored inside the bag.
Among such packaging bags, there are some that allow the contents, such as food or drink, to be heated and cooked in a microwave oven or the like while the contents are stored inside the bag.

Patent Document 1 discloses a packaging bag that, when the contents of the packaging bag, such as food or beverage, are heated together with the bag in a microwave oven or the like, allows steam to escape sufficiently outside the bag, there is no risk of the zipper part coming off unintentionally, and the contents of the food or beverage can be sufficiently steamed by heating.

The invention of Patent Document 1 is a packaging bag having a bag body having an opening at the top and a zipper part bonded to the inner surface of the bag body near the opening. The zipper part is composed of a first part having a male part and a first base and a second part having a female part and a second base, which are bonded to the inner surface at opposing positions. The first base and/or the second base have an unbonded area between the inner surface and the first base and/or the second base, and at least one passageway through which air can pass is formed between the inner surface of the bag body and the first base and/or the second base in the unbonded area, the opening diameter of the opening side end of the passageway is larger than the opening diameter of the bottom side end of the bag body, and the passageway has a straight part extending from the bottom side end with the same opening diameter as the opening diameter of the bottom side end, and an enlarged part whose opening diameter increases from the end of the straight part toward the opening side end. It is said that the shape of this passage allows steam generated within the bag body to escape more easily and stably to the outside of the bag body when the contents, such as food or drink, are heated together with the packaging bag of the present invention in a microwave oven or the like.

The passage connects the inside of the bag body to the outside of the bag, so it allows steam to escape to the outside, but at the same time, liquid placed in the bag body can also leak out of the bag through the passage. Therefore, when liquid is sealed inside the bag at the food manufacturer, the bag opening above the zipper is heat sealed to completely seal the opening. This prevents liquid from leaking out of the bag. However, since the passage is provided between the zipper (the first base and/or second base) and the inner surface, and the passage and the zipper are not separate, liquid leaking from the passage reaches the zipper and the entire inner surface near the opening where the zipper is attached, contaminating the entire inner surface near the opening.

As described above, conventional packaging bags have problems in that leaked liquid rises above the mating part between the zipper parts and contaminates the inner surface near the opening where the zipper parts are glued, resulting in an unattractive appearance, and when a consumer cuts open the top of the bag that has been heat-sealed by the food manufacturer to expose the zipper part and then tries to add ingredients to the liquid by opening the zipper, the liquid that has leaked into the zipper part sticks to their fingers.

Patent No. 6959845

The objective of this invention is to provide a packaging bag that avoids the deterioration of appearance caused by leaked liquid rising above the mating portion between the zipper parts and contaminating the inner surface near the opening where the zipper parts are attached, prevents liquid leaked into the zipper part from sticking to the fingers of a consumer who cuts open the zipper after exposing the zipper part by cutting the upper part of the bag that has been heat-sealed by the food manufacturer to add ingredients to the liquid, allows steam to escape sufficiently outside the bag when the contents of food or drink are heated together with the packaging bag in a microwave oven or the like, prevents the zipper part from coming off unintentionally, and allows the steaming effect of heating the contents of food or drink to be fully obtained.

The invention according to claim 1 is a packaging bag having an opening at the top, the packaging bag including a front film constituting a front side and a back film constituting a back side, a first portion of a zipper portion is adhered to an inner surface of the front film of the packaging bag near the opening, and a second portion of the zipper portion engageable with the first portion of the zipper portion is adhered to an inner surface of the back film of the packaging bag near the opening , the packaging bag including a bag lower body portion extending from a bottom to the zipper portion and a bag upper body portion extending from the zipper portion to the opening, and a zipper portion is provided between the front film and the first portion of the zipper portion and/or between the back film and the front The present invention relates to a packaging bag, characterized in that a strip film is provided between the second portions of the zipper portions, and an unadhesive portion is provided between the strip film and the front film and/or the strip film and the back film, the vertical width of the strip film is wider than the vertical width of the zipper portions, the unadhesive portion includes at least one passage that allows ventilation between the lower body portion and the upper body portion of the bag, the strip film is adhered to the front film and/or the back film on the entire surface other than the passage, and the opening width of the passage on the upper body portion side of the bag is larger than the opening width of the passage on the lower body portion side of the bag.

The invention according to claim 2 relates to the packaging bag according to claim 1, characterized in that the strip film contains at least a first composition and a second composition in this order from the inside of the packaging bag.

The invention of claim 3 relates to the packaging bag described in claim 2, characterized in that the heat fusion temperature of the first composition is different from the heat fusion temperature of the second composition, and the second portion of the zipper portion and the first composition constituting the strip film and/or the first portion of the zipper portion and the first composition constituting the strip film are heat fused.

The invention of claim 4 relates to a packaging bag described in any one of claims 1 to 3, characterized in that the adhesive portion between the belt -shaped film and the front film and/or the back film in the upper body portion of the bag seals the passage from the outside of the bag.

The invention of claim 5 relates to a packaging bag according to any one of claims 1 to 4, characterized in that it can be heated in a microwave oven.

The invention of claim 6 relates to a packaging bag as described in any one of claims 1 to 5, characterized in that the ratio of the opening width of the passage on the bag lower body side to the opening width of the passage on the bag upper body side is 1:1.1 to 1:6.

The invention according to claim 7 relates to the packaging bag according to any one of claims 1 to 6, characterized in that the passage is provided in a central area in the direction in which the zipper portion extends.

The invention according to claim 8 relates to the packaging bag according to any one of claims 1 to 7, characterized in that the passages are spaced apart from one another.

The invention of claim 9 relates to a packaging bag as described in any one of claims 1 to 8, characterized in that both side portions connecting the end portion of the passage on the side of the lower bag body portion and the end portion of the passage on the side of the upper bag body portion are straight, curved, or have a shape that combines straight lines and curves.

The invention of claim 10 relates to a packaging bag as described in any one of claims 1 to 9, characterized in that the passage has a straight portion extending from the opening on the lower body side of the bag with the same opening width as the opening on the upper body side of the bag, and an enlarged portion whose opening diameter enlarges as it moves from the end of the straight portion toward the opening on the upper body side of the bag.

The invention of claim 11 relates to the packaging bag described in claim 10, characterized in that the straight portion extends beyond the first part of the zipper portion and/or the second part of the zipper portion to the bag upper body portion side, and the expanded portion is located on the bag upper body portion side rather than the first part of the zipper portion and/or the second part of the zipper portion.

The invention of claim 12 relates to the packaging bag according to any one of claims 1 to 11, characterized in that the bottom portion has a gusset portion so that the packaging bag can stand on its own.

According to the invention of claim 1, there is provided a packaging bag having an opening at an upper portion, the packaging bag including a front film constituting a front side and a back film constituting a back side, a first portion of a zipper portion is adhered to an inner surface of the front film of the packaging bag near the opening, and a second portion of the zipper portion engageable with the first portion of the zipper portion is adhered to an inner surface of the back film of the packaging bag near the opening, the packaging bag includes a bag lower body portion extending from a bottom to the zipper portion and a bag upper body portion extending from the zipper portion to the opening, a strip film is provided between the front film and the first portion of the zipper portion and/or between the back film and the second portion of the zipper portion, and an unadhesive portion is provided between the strip film and the front film and/or the strip film and the back film , a vertical width of the strip film is wider than a vertical width of the zipper portion, and the unadhesive portion is disposed between the bag lower body portion and the first portion of the zipper portion. and at least one passage that allows ventilation between the body and the upper body of the bag, the band-shaped film is adhered to the front film and/or the back film on the entire surface other than the passage, and the opening width of the passage on the upper body side of the bag is larger than the opening width of the passage on the lower body side of the bag , so that a deterioration in appearance due to leaked liquid rising above the fitting portion between the zipper portions and contaminating the inner surface near the opening where the zipper portions are adhered is avoided, when a consumer cuts open the upper part of the bag that has been heat-sealed by the food manufacturer to expose the zipper portion and then opens the zipper to add ingredients to the liquid, the liquid that has leaked into the zipper portion does not stick to his or her fingers, and when the contents, such as food or beverage, are heated together with the packaging bag in a microwave oven or the like, steam can be sufficiently released outside the bag, there is no risk of the zipper portion coming off unintentionally, and the steaming effect of heating the contents, such as food or beverage, can be fully obtained.
In addition, the packaging bag includes a lower bag body portion extending from the bottom to the zipper portion and an upper bag body portion extending from the zipper portion to the opening, and the unbonded portion includes at least one passage that allows ventilation between the lower bag body portion and the upper bag body portion, so that when the contents, such as food or beverage, are heated together with the packaging bag in a microwave oven or the like, steam can be sufficiently allowed to escape outside the bag body through the passage.
Furthermore, the strip film is adhered to the front film and/or back film on the entire surface except the passage, and the opening width of the passage on the upper body side of the bag is larger than the opening width of the passage on the lower body side of the bag, so that a pressure difference can be created in the passage such that the pressure decreases from the bottom end toward the opening end.

According to the invention of claim 2 , the strip film contains at least a first composition and a second composition in that order from the inside of the packaging bag, so that the second portion of the zipper part and the first composition constituting the strip film and/or the first portion of the zipper part and the first composition constituting the strip film are heat-sealed, whereby liquid such as liquid seasoning sealed in the packaging bag by a food manufacturer or the like can be transported to a consumer without leaking from the packaging bag.

According to the invention of claim 3, the heat fusion temperature of the first composition is different from the heat fusion temperature of the second composition, and the second portion of the chuck portion and the first composition constituting the strip-shaped film and/or the first portion of the chuck portion and the first composition constituting the strip-shaped film are heat fused together, so that liquids such as liquid seasonings sealed in packaging bags by food manufacturers, etc. can be transported to consumers without leaking from the packaging bags.

According to the invention of claim 4, the adhesive portion of the belt - shaped film and the front film and/or the back film in the upper body of the bag seals the passage from the outside of the bag, so that liquid seasoning or other liquid can be transported to the consumer without leaking when the liquid seasoning or other liquid is sealed in the packaging bag by a food manufacturer or the like. The consumer transports the liquid seasoning or other liquid with the passage sealed, and cuts off the sealed portion when cooking. In this way, the passage connects the inside of the bag to the outside, and when the contents such as food or drink are heated together with the packaging bag in a microwave oven or the like, steam can be sufficiently released outside the bag through the passage.

According to the invention of claim 5, since heating in a microwave oven is possible, the contents of the packaging bag of the present invention, such as food and drink, can be heated and cooked in a microwave oven or the like.

According to the invention of claim 6, the ratio of the opening width of the passage on the lower body side of the bag to the opening width of the passage on the upper body side of the bag is 1:1.1 to 1:6, so that when the contents, such as food or beverage, are heated together with the packaging bag of the present invention in a microwave oven or the like, a large pressure difference can be created in the passage so that the pressure decreases from the bottom end toward the opening end.
Due to the large pressure difference formed, steam from the lower body of the bag can be smoothly released to the outside. When the contents of the packaging bag of the present invention, such as food or drink, are heated together with the bag in a microwave oven or the like, the pressure inside the bag can be maintained to such an extent that the fitting parts of the zippers do not come apart, and by reducing the opening width on the lower body side, rapid steam escape can be prevented, so that the steaming effect of heating the contents, such as food or drink, can be fully obtained.

According to the invention of claim 7, the passage is provided in one position at the center in the direction in which the zipper portion extends, so that when the contents, such as food or beverage, are heated together with the packaging bag of the present invention in a microwave oven or the like, steam generated within the packaging bag can be more easily released to the outside of the packaging bag.
Furthermore, when the contents, such as food or beverage, are heated together with the packaging bag of the present invention in a microwave oven or the like, steam inside the packaging bag escapes from the center in the direction in which the zipper portion extends, thereby preventing deformation of the packaging bag and making it possible to more easily and stably achieve the effects of the inventions of claims 1 to 6.

According to the invention of claim 8, the passages are spaced apart from one another, so that when the contents of the packaging bag of the present invention, such as food or drink, are heated in a microwave oven or the like, the steam generated in the packaging bag can be more easily and stably released to the outside of the packaging bag.

According to the invention of claim 9, the side portions of the passage connecting the end portion on the lower body side of the bag and the end portion on the upper body side of the bag are straight, curved, or have a shape that combines straight and curved lines, so that when the contents, such as food or beverage, are heated together with the packaging bag of the present invention in a microwave oven or the like, the amount of steam escaping can be adjusted to the desired amount.
In addition, the passage can be formed in a highly decorative shape.

According to the invention of claim 10, the passage has a straight portion extending from the opening on the lower body side of the bag with the same opening width as the opening on the upper body side of the bag, and an enlarged portion whose opening diameter expands as it moves from the end of the straight portion toward the opening on the upper body side of the bag.Therefore , when the contents, such as food or beverage, are heated together with the packaging bag of the present invention in a microwave oven or the like, steam generated inside the packaging bag can be more easily and stably released to the outside of the packaging bag.

According to the invention of claim 11, the straight portion extends beyond the first part of the zipper portion and/or the second part of the zipper portion to the bag upper body portion side, and the expanded portion is located closer to the bag upper body portion side than the first part of the zipper portion and/or the second part of the zipper portion, so that the straight portion of the passage is less likely to bulge and the expanded portion is more likely to bulge.
This prevents the contents from leaking out of the packaging bag through the straight portion of the passage, and because the passage in the expansion section is prone to expanding, a pressure difference can be more easily created in the passage so that the pressure decreases from the end on the lower body side of the bag toward the end on the upper body side of the bag, making it easier to expel steam outside the packaging bag.

According to the invention of claim 12, the bottom has a gusset portion so that the packaging bag can stand on its own. Therefore, when the contents of the packaging bag of the present invention, such as food or drink, are heated together with the packaging bag in a microwave oven or the like, the packaging bag can be kept upright, and steam generated within the packaging bag can be more easily and stably released to the outside of the packaging bag.

FIG. 1(a) is a front view of a packaging bag according to the present invention, and FIG. 1(b) is an explanatory diagram of a portion indicated by region X in FIG. 1(a). 2(a) is a cross-sectional view taken along line AA of the packaging bag shown in FIG. 1, and FIG. 2(b) is an enlarged view of a portion indicated by region Y in FIG. 2(a). 3A is a cross-sectional view of the packaging bag shown in FIG. 1 taken along line BB, and FIG. 3B is a cross-sectional view of the packaging bag shown in FIG. 1 taken along line CC. 4(a) is a three-dimensional development view of the packaging bag shown in FIG. 1, and FIG. 4(b) is an enlarged view of a portion indicated by region Z in FIG. 4(a). (a) of Figure 5 is a cross-sectional view of the packaging bag shown in Figure 1 taken along line B-B, showing the state before the passage blocking portion is cut off, (b) of Figure 5 is a cross-sectional view of the packaging bag shown in Figure 1 taken along line C-C, showing the state before the passage blocking portion is cut off, (c) of Figure 5 is a cross-sectional view of the packaging bag shown in Figure 1 taken along line B-B, showing the state after the passage blocking portion has been cut off, and (d) of Figure 5 is a cross-sectional view of the packaging bag shown in Figure 1 taken along line C-C, showing the state after the passage blocking portion has been cut off. Fig. 6(a) is a front view of the packaging bag according to the present invention in a state where a food manufacturer or the like is filling the bag with food or the like. Fig. 6(b) is a cross-sectional view of the packaging bag shown in Fig. 6(a) taken along line B-B. Fig. 6(c) is a cross-sectional view of the packaging bag shown in Fig. 6(a) taken along line C-C. Fig. 7(a) is a front view of the packaging bag according to the present invention in a state in which it is shipped by a food manufacturer, etc. Fig. 7(b) is a cross-sectional view of the packaging bag shown in Fig. 7(a) taken along line B-B. Fig. 7(c) is a cross-sectional view of the packaging bag shown in Fig. 7(a) taken along line C-C. Fig. 8(a) is a front view of the packaging bag according to the present invention in a state before a consumer uses a microwave oven to cook food. Fig. 8(b) is a cross-sectional view of the packaging bag shown in Fig. 8(a) taken along line B-B. Fig. 8(c) is a cross-sectional view of the packaging bag shown in Fig. 8(a) taken along line C-C. Fig. 9(a) is a front view of the packaging bag according to the present invention when a consumer is cooking food in a microwave oven. Fig. 9(b) is a cross-sectional view of the packaging bag shown in Fig. 9(a) taken along line B-B. Fig. 9(c) is a cross-sectional view of the packaging bag shown in Fig. 9(a) taken along line C-C. Fig. 10(a) is a front view of the packaging bag according to the present invention in a state where a consumer takes out cooked food. Fig. 10(b) is a cross-sectional view of the packaging bag shown in Fig. 10(a) taken along line B-B. Fig. 10(c) is a cross-sectional view of the packaging bag shown in Fig. 10(a) taken along line C-C.

Hereinafter, preferred embodiments of the packaging bag according to the present invention will be described with reference to the accompanying drawings.
Fig. 1(a) is a front view of the packaging bag according to the present invention, and Fig. 1(b) is an explanatory diagram of the portion indicated by region X in Fig. 1(a). Fig. 2(a) is a cross-sectional view of the packaging bag shown in Fig. 1 taken along line A-A, and Fig. 2(b) is an enlarged view of the portion indicated by region Y in Fig. 2(a). Fig. 3(a) is a cross-sectional view of the packaging bag shown in Fig. 1 taken along line B-B, and Fig. 3(b) is a cross-sectional view of the packaging bag shown in Fig. 1 taken along line C-C. Fig. 4(a) is a three-dimensional development view of the packaging bag shown in Fig. 1, and Fig. 4(b) is an enlarged view of the portion indicated by region Z in Fig. 4(a). Fig. 5(a) is a cross-sectional view of the packaging bag shown in Fig. 1 taken along line B-B, showing the state before the passage blocking portion is cut off, Fig. 5(b) is a cross-sectional view of the packaging bag shown in Fig. 1 taken along line C-C, showing the state before the passage blocking portion is cut off, Fig. 5(c) is a cross-sectional view of the packaging bag shown in Fig. 1 taken along line B-B, showing the state after the passage blocking portion is cut off, and Fig. 5(d) is a cross-sectional view of the packaging bag shown in Fig. 1 taken along line C-C, showing the state after the passage blocking portion is cut off. Fig. 6(a) is a front view of the packaging bag according to the present invention in a state in which a food manufacturer or the like is filling the packaging bag with food or the like. Fig. 6(b) is a cross-sectional view of the packaging bag shown in Fig. 6(a) taken along line B-B. Fig. 6(c) is a cross-sectional view of the packaging bag shown in Fig. 6(a) taken along line C-C. Fig. 7(a) is a front view of the packaging bag according to the present invention in a state in which a food manufacturer or the like is shipping the packaging bag. Fig. 7(b) is a cross-sectional view of the packaging bag shown in Fig. 7(a) taken along line B-B. Fig. 7(c) is a cross-sectional view of the packaging bag shown in Fig. 7(a) along line C-C. Fig. 8(a) is a front view of the packaging bag according to the present invention before a consumer uses a microwave oven to cook food. Fig. 8(b) is a cross-sectional view of the packaging bag shown in Fig. 8(a) along line B-B. Fig. 8(c) is a cross-sectional view of the packaging bag shown in Fig. 8(a) along line C-C. Fig. 9(a) is a front view of the packaging bag according to the present invention while a consumer uses a microwave oven to cook food. Fig. 9(b) is a cross-sectional view of the packaging bag shown in Fig. 9(a) along line B-B. Fig. 9(c) is a cross-sectional view of the packaging bag shown in Fig. 9(a) along line C-C. Fig. 10(a) is a front view of the packaging bag according to the present invention when a consumer takes out cooked food. Fig. 10(b) is a cross-sectional view of the packaging bag shown in Fig. 10(a) along line B-B. Fig. 10(c) is a cross-sectional view of the packaging bag shown in Fig. 10(a) along line C-C.

[Front and back films]
According to Figures 1 and 2, the packaging bag (1) of the present invention has a front film (2) and a back film (3) overlapped, and has a left end (4), a right end (5), and a bottom (6) that close the overlapped front film (2) and back film (3) by heat sealing.

There is no particular limitation on the method for sealing the front film (2) and the back film (3), and any commonly used sealing method such as heat fusion can be used.
For example, in the case of heat fusion, a pair of opposing sides of the front film (2) and the back film (3) can be fused by heat fusion. Furthermore, adhesives that are commonly used for heat fusion, such as EVA (ethylene vinyl acetate copolymer), PO (polyolefin), PA (polyamide), SR (synthetic rubber (styrene rubber)), ACR (acrylic), and PUR (polyurethane resin) hot melt adhesives, may be used.
Incidentally, the heat sealing method is not limited to the above-mentioned method, and any method that can seal a pair of opposing sides of the front film (2) and the back film (3) that are opposed to each other and that is obvious to a person skilled in the art can be used.

Any material may be used for the front film (2) and the back film (3), but it is preferable that the outer surface of the bag is a base layer and the inner surface of the bag is a sealant layer.
Examples of the substrate layer include biaxially oriented polypropylene film (OPP), biaxially oriented nylon film (ONY), polyethylene terephthalate (PET), biaxially oriented polyethylene terephthalate (OPET), non-oriented polypropylene film, non-oriented nylon film, cellulose-based film, synthetic paper, etc. These materials may be made from recycled or biomass-derived raw materials. The substrate layer may be composed of two or more layers.
The substrate layer may also have a gas barrier layer, an adhesive resin layer, an anchor coating layer, a vapor deposition layer (ceramic vapor deposition layer, etc.), a printing layer, a top coat layer, or the like.
The gas barrier layer may be made of PVDC (polyvinylidene chloride), acrylic resin, organic material, inorganic compound, or the like.
The thickness of the substrate layer is arbitrary as long as it has a predetermined strength, but is often set to, for example, about 12 to 120 μm.

Examples of sealant layers include layers of various resins with heat fusion properties, including polyethylene-based resins such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), ethylene-vinyl acetate copolymer (EVA), and ethylene-unsaturated carboxylic acid copolymer, and polypropylene-based resins known as CPP. These materials may be made from recycled or biomass-derived raw materials. The sealant layer may be composed of two or more layers. There are no particular limitations on the thickness of the sealant layer, but it is often about 10 to 250 μm, and especially about 20 to 200 μm.

Except when forming a vapor deposition layer, lamination between each layer is performed by methods such as dry lamination (DL), wet lamination, casting, sand lamination, co-extrusion, extrusion coating, and printing.

As a suitable example in the present invention, when biaxially oriented nylon (ONY) having a melting point of 215 to 225°C or polyethylene terephthalate (PET) having a melting point of 265°C is used as the material of the synthetic resin film used in the base layer, the following may be selected as the material of the synthetic resin film used in the sealant layer: low density polyethylene (LDPE) having a melting point of 105 to 115°C, medium density polyethylene (MDPE) having a melting point of 110 to 130°C, linear low density polyethylene (LLDPE) having a melting point of 125 to 130°C, high density polyethylene (HDPE) having a melting point of 135 to 150°C, or non-oriented polypropylene (CPP) having a melting point of 135 to 165°C.

[Chuck part]
1 to 4, the packaging bag (1) according to the present invention further has a zipper part (8) adhered to the inner surface near the opening (7) of the packaging bag (1). The zipper part (8) is composed of a linear first part (9) and a linear second part (10) that can be engaged with the first part (9).
The structure of the first part (9) and the second part (10) of the chuck part (8) according to the present invention is not particularly limited. The first part (9) and the second part (10) can be repeatedly engaged and disengaged, and any structure that is normally used as the male and female parts (or vice versa) of the chuck part (8) can be used.

As shown in Figures 2(a) and 4(a), the first portion (9) of the chuck portion (8) has a length equal to the width of the front film (2) and the back film (3). The first portion (9) of the chuck portion (8) is bonded to the inner surface of the front film (2) such that the first tip portion (11) and the second tip portion (12) of the first portion of the chuck portion (8) reach the left end (4) and the right end (5) of the front film (2), respectively.
The second portion (10) of the chuck portion (8) has a length equal to the width of the front film (2) and the back film (3). The second portion (10) of the chuck portion (8) is adhered to the inner surface of the back film (3) via a strip film (24) at a position opposite to the first portion (9) of the chuck portion (8).

[Belt film]
As shown in FIG. 2(a) and FIG. 4(a), the strip film (24) has a length equal to the width of the front film (2) and the back film (3).
The first tip (13) and the second tip (14) of the second part of the chuck portion are adhered to the first surface (18) of the strip film (24) (see FIG. 2(b)) so as to reach the left end (15) and the right end (16) of the strip film, respectively.

The second surface (17) of the strip film (see FIG. 2(b)) is first adhered to the inner surface of the backing film (3) so that the second portion (10) of the zipper portion (8) adhered to the first surface (18) of the strip film faces the first portion (9) of the zipper portion (8), then the left end (15) and right end (16) of the strip film reach the left end (4) and right end (5) of the backing film (3), and then one long side (19) of the strip film (24) coincides with the end of the opening (7) of the backing film (3).

The strip film (24) preferably contains at least a first composition and a second composition in that order from the inside of the packaging bag (1), and the first composition and the second composition may be low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), or polypropylene (PP). The heat fusion temperature of the first composition is preferably lower than the heat fusion temperature of the second composition. It goes without saying that the strip film of the present invention includes a third composition in addition to the first composition and the second composition.
2, the heat-sealing temperature of the first composition is lower than that of the second composition, so that the first surface (18) of the strip film (24) and the second portion (10) of the zipper portion (8) are bonded by heat sealing, and liquid leakage from the packaging bag (1) before cooking can be prevented. Meanwhile, the second surface (17) of the strip film (24) and the back film (3) are not bonded, so that a passage (30) that functions during cooking and allows ventilation between the lower bag portion (22) and the upper bag portion (23) can be formed between the second surface (17) of the strip film (24) and the back film (3).

[Unbonded area]
However, the second surface (17) of the strip film (24) is not entirely bonded to the inner surface of the back film (3), but includes an unbonded portion (21) which is partially unbonded, as shown in Figures 1, 2 and 4. The unbonded portion (21) is provided in the center of the longitudinal direction of the strip film (24). As shown in Figures 1(b) and 4(b), the unbonded portion (21) is made up of a passage (30) (described later) and an open space (33) located above the passage (30).

The longitudinal cross-sectional structure of the unbonded portion (21) and the bonded portion is shown in Figure 3. As shown in Figure 3(a), it can be seen that only a portion of the belt-shaped film (24) in the longitudinal direction is bonded to the inner surface of the back film (3) in the B-B cross section. This unbonded area is the aforementioned unbonded portion (21).
On the other hand, as shown in FIG. 3(b), in the cross section cut along line C-C, there is no unbonded portion (21), and therefore the belt-like film (24) is bonded to the inner surface of the back film (3) over the entire longitudinal area.

The packaging bag (1) includes a bag lower body portion (22) extending from the bottom portion (6) to the zipper portion (8) and a bag upper body portion (23) extending from the zipper portion (8) to the opening portion (7).
The unbonded portion (21) is provided across two portions, the lower bag portion (22) and the upper bag portion (23). Thus, a part of the unbonded portion (21) that connects the two portions functions as a passage (30).
In the embodiment shown in Figure 3, a configuration is shown as an example in which a strip film (24) is inserted between the back film (3) and the second portion (10) of the zipper portion (8) and an unbonded portion (21) is provided between the second surface (17) of the strip film (24) and the back film (3), but the packaging bag (1) in this embodiment is not limited to this configuration.
For example, the strip film (24) may be inserted between the front film (2) and the first portion (9) of the zipper portion (8), and in this case, an unbonded portion (21) may be provided between the second surface (17) of the strip film (24) and the front film (2). Also, the unbonded portion (21) may be provided both between the second surface (17) of the strip film (24) and the front film (2) and between the second surface (17) of the strip film (24) and the back film (3).

[aisle]
As shown in Figures 1(b) and 4(b), the passage (30) includes a straight section (31) in the bag lower body section (22) and an inverted trapezoidal enlarged section (32) whose opening diameter increases from the end of the straight section (31) toward the end on the upper body section side.
The straight portion (31) extends beyond the second portion (10) of the chuck portion (8) to the upper body side.
The enlarged portion (32) is located closer to the upper body portion than the second portion (10) of the zipper portion (8). Due to the enlarged portion (32), the width (36) of the opening on the upper body portion side of the bag is larger than the width (35) of the opening on the lower body portion side of the bag.

[Passage blockage]
As shown in Figures 1(b), 4(b) and 3(a), there is a region (34) in the vicinity of the end of the opening (7) where the second surface (17) of the strip film is bonded to the inner surface of the back film (3). This bonded portion (hereinafter referred to as the passage closing portion (34)) closes the passage (30) from the outside of the bag.
Due to the passage blocking portion (34), the lower body portion (22) of the bag communicates with the unbonded portion (21) of the upper body portion (23) of the bag, but does not communicate with the outside of the bag.

It is assumed that the passage blocking portion (34) will be cut off in advance. The cutting position will be described later. (a) and (b) of FIG. 5 show the B-B and C-C cross sections, respectively, before the passage blocking portion (34) is cut off, and (c) and (d) of FIG. 5 show the B-B and C-C cross sections, respectively, after the passage blocking portion (34) is cut off. Before the passage blocking portion (34) is cut off, the passage blocking portion (34) does not connect the outside of the bag to the lower bag portion (22) in the B-B cross section. By cutting off the passage blocking portion (34), the passage (30) between the strip film (24) and the back film (3) becomes connected to the outside of the bag in the B-B cross section. The state of the C-C cross section does not change before or after the passage blocking portion (34) is cut off, so the outside of the bag is not connected to the lower bag portion (22). By cutting out the passage blocking portion (34) in this manner, communication between the outside of the bag and the bag lower body portion (22) becomes possible at cross section B-B.

[Cooking procedure using the packaging bag according to the present invention]
Figures 6 to 10 show the process of sealing, transporting and cooking liquid such as liquid seasoning (40) in the packaging bag (1) of the present invention. First, the food manufacturer opens the first part (9) and the second part (10) of the zipper part (8) as shown in Figures 6(b) and 6(c) to open the bag lower body part (22) to the outside, and then pours liquid such as liquid seasoning (40) from the outside. Figure 6(a) shows a front view of the bag with liquid such as liquid seasoning (40) poured in.

Next, the food manufacturer heat-seals the strip film (24) joined to the front film (2) and back film (3) at the top of the bag upper body (23) to create the heat-sealed portion (41). The front view after heat-sealing is shown in FIG. 7(a), the B-B cross section in FIG. 7(b), and the C-C cross section in FIG. 7(c). By doing this, even if the first part (9) and the second part (10) of the zipper part (8) are opened for some reason, the liquid such as liquid seasoning (40) in the lower body part (22) is blocked by the heat-sealed portion (41) and will not leak out of the bag. In this state, the liquid such as liquid seasoning (40) sealed in the lower body part (22) is transported and delivered to the consumer.

After that, the consumer cuts off the passage blocking portion (34) at the cutting line (37) shown in FIG. 7(a) during cooking. The cutting line (37) may be made by half-cut processing using laser irradiation. There may be notches (38) at both ends of the cutting line (37). The front view after cutting is shown in FIG. 8(a), the B-B cross section is shown in FIG. 8(b), and the C-C cross section is shown in FIG. 8(c). Cutting off the passage blocking portion (34) has two purposes. One is to open the heat-sealed portion (41) of the front film (2) and the back film (3). This allows the consumer to access the first part (9) and the second part (10) of the zipper part (8). The consumer can open the first part (9) and the second part (10) of the zipper part (8) to touch liquid such as liquid seasoning (40). Another meaning is that, as mentioned above, the passage (30) allows communication between the outside of the bag and the bag lower body portion (22) at the B-B cross section.

Furthermore, as shown in FIG. 8(b), the consumer opens the first part (9) and the second part (10) of the zipper part (8) and puts ingredients (42) such as vegetables and meat into the liquid such as liquid seasoning (40). At this time, as shown in FIG. 8(b), the B-B cross section has a passage (30) that connects the bag lower body part (22) to the outside of the bag, and the passage (30) may be contaminated with the liquid such as the liquid seasoning (40) sealed in the bag lower body part (22). However, the passage (30) is provided between the strip film (24) and the back film (3) as described above, and the strip film (24) separates the zipper part (8) from the passage (30). Therefore, under normal use, the contamination of the passage (30) does not reach the zipper part (8). Even if the zipper portion (8) at cross section B-B becomes contaminated for some reason, since there is no passage (30) at cross section C-C, liquid such as liquid seasoning (40) sealed in the lower body portion (22) will not contaminate the zipper portion (8) at cross section C-C.

At any location in the width direction of the packaging bag (1), including the B-B cross section and the C-C cross section, the consumer can pinch and spread the first part (9) and the second part (10) of the zipper part (8) with the fingers (43) to open the zipper part (8) without touching the liquid such as the sprayed liquid seasoning (40). Furthermore, if the consumer pinches and spreads the first part (9) and the second part (10) of the zipper part (8) with the fingers (43) at a location other than the B-B cross section (e.g., the C-C cross section), the consumer can open the zipper part (8) more reliably without touching the liquid such as the sprayed liquid seasoning (40) compared to pinching and spreading the zipper part (8) with the fingers (43). The C-C cross section in FIG. 8(c) shows how the zipper part (8) is pinched and removed with the fingers (43) to open the bag.
After this, the consumer seals the first part (9) and the second part (10) of the zipper part (8) as shown in (a), (b) and (c) of FIG. 9. Even if the zipper part is sealed, the outside of the bag and the lower part (22) of the bag are in communication with each other through the passage (30). Therefore, the steam generated in the lower part (22) of the bag when heated in a microwave oven can be released to the outside, so that the steam pressure inside the bag does not become abnormally high, there is no risk of the zipper part (8) coming off unintentionally, and the pressure inside the bag can be maintained to a level that does not cause the fitting parts of the zipper parts to come off, so that liquids such as liquid seasonings (40) and ingredients (42) can be cooked easily and safely. As shown in (b) of FIG. 9, the steam generated by cooking is discharged from the passage (30) between the strip film (24) and the back film (3) at the B-B cross section. As shown in (c) of FIG. 9, there is no passage at the C-C cross section, so the steam is not discharged.

Furthermore, the consumer removes the cooked food from the bag. Figure 10 shows how the food is removed from the bag. As shown in Figure 10 (b), a passage (30) is provided at cross section B-B that connects the bag lower body portion (22) to the outside of the bag, and this passage (30) may be contaminated with liquid such as liquid seasoning (40) that is sprayed out together with steam. However, for the reasons mentioned above, contamination of the passage (30) does not extend to the zipper portion (8) under normal use.

At any location in the width direction of the packaging bag (1), including the B-B cross section and the C-C cross section, the consumer can pinch and spread the first part (9) and the second part (10) of the zipper part (8) with the fingers (43) to open the first part (9) and the second part (10) of the zipper part (8) without touching the liquid such as the spurted liquid seasoning (40). The view showing the C-C cross section in Figure 10(c) shows how the zipper part (8) is pinched and removed with the fingers (43) to open it.

In the packaging bag according to Patent Document 1 described in the Background Art section, the passage (30) connecting the bag lower body (22) to the outside of the bag is provided between the zipper part (8) and the inner surface of the backing film (3), and the passage (30) and the zipper part (8) are not separate structures. Therefore, liquid leaking from the passage (30) contaminates the zipper part (8) and the entire inner surface in the vicinity of the opening (7) where the zipper part (8) is adhered, causing a problem that fingers are stained when the zipper part (8) is opened.

In the packaging bag according to the present invention, the zipper part (8) is adhered to the back film (3) via the strip film (24), and a passage (30) that is not adhered is provided between the strip film (24) and the back film (3). By adhering the strip film (24) and the zipper part (8), the passage (30) and the zipper part (8) are configured separately, and contamination by liquid leaking from the passage (30) does not reach the zipper part (8). As a result, the problem of getting fingers dirty when opening the zipper part (8) can be avoided.

[Shape of the aisle]
Regarding the shape of the passageway (30), the shape of the passageway plays a very important role in the cooking process in a microwave oven.
As shown in FIG. 1(b), in the packaging bag (1) of the present invention, the length of the opening (36) on the bag upper body side in the passage (30) is greater than the length of the opening (35) on the bag lower body side.
Due to the difference in the opening width, when steam is generated inside the lower bag body part (22) during cooking in a microwave oven, a pressure difference can be created so that the pressure decreases from the opening of the passage (30) on the lower bag body part side toward the opening on the upper bag body part side.
This pressure difference makes the pressure in the lower body portion (22) slightly higher than the pressure outside the bag. However, at the same time, the pressure difference creates a flow of steam from the opening on the lower body side of the bag toward the opening on the upper body side of the bag. This flow of steam releases the steam to the outside, suppressing excessive pressure rise in the lower body portion (22). By making the pressure in the lower body portion (22) slightly higher than the pressure outside the bag, it is possible to fully obtain the steaming effect on the contents, such as food and beverages, by heating, and by suppressing excessive pressure rise in the lower body portion (22), there is no risk of the zipper portion (8) coming off unintentionally.

The ratio of the length of the opening (36) on the upper bag body side in the passage (8) to the length of the opening (35) on the lower bag body side is not particularly limited, but is preferably 1:1.1 to 1:6.
If the above ratio is less than 1:1.1 (i.e., 1:<1.1), when the contents such as food and beverage are heated together with the packaging bag (1) of the present invention in a microwave oven or the like, the pressure difference between the opening (35) on the lower body side of the bag and the opening (36) on the upper body side of the bag is small, so there is a risk that steam will not be able to escape effectively from the opening (36) on the upper body side of the passage (30), which is undesirable.
If the above ratio is greater than 1:6 (i.e., 1:>6), when the contents, such as food or beverage, are heated together with the packaging bag (1) of the present invention in a microwave oven or the like, there is a risk that too much steam will escape from the opening (36) on the upper body side of the passage (30), which is undesirable.
Therefore, the ratio of the length of the opening (36) on the upper bag body side in the passage (4) to the opening width (35) on the lower bag body side is desirably 1:1.1 to 1:6, so that when the contents, such as food or beverage, are heated together with the packaging bag (1) of the present invention in a microwave oven or the like, steam can be sufficiently released outside the lower bag body portion (22), there is no risk of the zipper portion (3) being unintentionally detached, and the steaming effect on the contents, such as food or beverage, due to heating can be sufficiently obtained.

The opening width (35) on the lower bag body side of the passage (30) and the length of the opening (36) on the upper bag body side are not particularly limited, and it is desirable to select them appropriately depending on the size of the packaging bag (1) of the present invention and the desired amount of steam escape.
As described above, the length of the opening (35) of the passage (30) on the side of the lower body portion of the bag can be appropriately selected, and can be, for example, 5 mm or more and 50 mm or less.
For example, when the length of the opening (35) of the passage (30) on the lower body side of the bag is 5 mm, the length of the opening (36) of the passage (30) on the upper body side of the bag is desirably 5.5 mm or more and 30 mm or less.

The number and position of the passages (30) provided in the packaging bag (1) of the present invention are not particularly limited, and it is desirable to select them appropriately depending on the size of the packaging bag (1) of the present invention and the desired amount of vapor escape.
When one passage (30) is provided in the packaging bag (1) of the present invention, it is desirable to provide the passage (30) at the center in the width direction of the packaging bag (1).
By providing a passage (30) in the center of the zipper portion (8) of the packaging bag (1), when the contents, such as food or beverage, are heated together with the packaging bag (1) of the present invention in a microwave oven or the like, steam escapes from the center of the zipper portion (8) of the packaging bag (1), allowing the steam to escape without causing significant deformation of the shape of the packaging bag (1), and allowing the steam generated within the bag lower body portion (2) to escape to the outside of the packaging bag (1) more easily and stably.
However, even if the passage (30) is provided at a location other than the center of the chuck portion (8), the effects of the present invention can be achieved.

Also, a plurality of passages (30) may be provided along the chuck portion (8). The plurality of passages (30) are provided at intervals from each other.
By providing multiple passages (30), when the contents, such as food or beverage, are heated together with the packaging bag (1) of the present invention in a microwave oven or the like, steam generated within the lower body portion of the bag can be more easily and stably released to the outside of the packaging bag (1).

As described above, the passage (30) may have any shape as long as the length of the opening (36) on the upper body side of the bag is longer than the length of the opening (35) on the lower body side of the bag, and the sides of the passage (30) connecting the end of the opening (35) on the lower body side of the bag and the end of the opening (36) on the upper body side of the bag may be straight, curved, or a combination of straight and curved shapes.

Next, examples of the packaging bag of the present invention will be described in detail, but the present invention is not limited to these examples.
After the packaging bag according to the present invention was produced, the functionality of the packaging bag was checked.
First, a liquid leakage test was conducted on the heat-sealed portion between the zipper and the strip of film. The packaging bag was filled with water, and pressure was applied while the bag was turned upside down to check whether there was any liquid leakage from the heat-sealed portion between the zipper and the strip of film. In addition, Ageless Checker liquid was sprayed on the heat-sealed portion between the zipper and the strip of film to check whether there was any liquid leakage.
Tests were conducted on five samples, and the results are shown in Table 1. As a result, no leakage was observed in any of the samples.

Secondly, a heating experiment was conducted in a microwave oven. The packaging bag was filled with 200 mL of water and heated in a microwave oven (600 W for 3 minutes). Five samples were tested. The results are shown in Table 2. As a result, it was confirmed that steam was conducted through the passage when heated, but the engagement between the zipper parts (8) did not come apart during heating in the microwave.

The present invention is suitably used to provide a packaging bag that avoids the deterioration of appearance caused by leaked liquid rising above the mating portion between the zipper parts and contaminating the inner surface near the opening where the zipper parts are attached, prevents liquid leaked into the zipper part from sticking to the fingers of a consumer who cuts open the zipper after exposing the zipper part by cutting the upper part of the bag that has been heat-sealed by the food manufacturer to add ingredients to the liquid, allows steam to escape sufficiently outside the bag when the contents of food or drink are heated together with the packaging bag in a microwave oven or the like, prevents the zipper part from coming off unintentionally, and allows the steaming effect of heating the contents of food or drink to be fully obtained.

1 Packaging bag 2 Front film 3 Back film 6 Bottom 7 Opening 8 Zipper 9 First part of zipper 10 Second part of zipper 21 Unbonded part 22 Lower body part of bag 23 Upper body part of bag 24 Strip film 30 Passage 31 Straight part 32 Enlarged part 35 Opening width of passage on the side of the lower body part of bag 36 Opening width of passage on the side of the upper body part of bag

Claims (12)

A packaging bag having an opening at the top,
The packaging bag includes a front film constituting a front side and a back film constituting a back side,
a first portion of a zipper portion is adhered to an inner surface of the outer film of the packaging bag in the vicinity of an opening;
A second part of the zipper part engageable with the first part of the zipper part is adhered to the inner surface of the back film of the packaging bag in the vicinity of an opening,
The packaging bag includes a bag lower body portion extending from a bottom portion to the zipper portion, and a bag upper body portion extending from the zipper portion to the opening portion,
a strip film is provided between the front film and a first portion of the zipper portion and/or between the back film and a second portion of the zipper portion, and an unbonded portion is provided between the strip film and the front film and/or between the strip film and the back film ;
The vertical width of the strip film is wider than the vertical width of the chuck portion,
the unbonded portion includes at least one passageway that allows ventilation between the lower bag portion and the upper bag portion, and the belt-shaped film is bonded to the front film and/or the back film on the entire surface other than the passageway,
A packaging bag, characterized in that an opening width of the passage on the bag upper body side is larger than an opening width of the passage on the bag lower body side . 2. The packaging bag according to claim 1, wherein the strip film comprises at least a first composition and a second composition in that order from the inside of the packaging bag. The heat fusion temperature of the first composition is different from the heat fusion temperature of the second composition,
The packaging bag according to claim 2, characterized in that the second portion of the zipper portion and the first composition constituting the strip film and/or the first portion of the zipper portion and the first composition constituting the strip film are heat - sealed. 4. The packaging bag according to claim 1, wherein the adhesive portion of the belt-shaped film and the front film and/or the back film in the upper body closes the passage from the outside of the bag. The packaging bag according to any one of claims 1 to 4, characterized in that it can be heated in a microwave oven. The packaging bag according to any one of claims 1 to 5, characterized in that the ratio of the opening width of the passage on the bag lower body side to the opening width of the passage on the bag upper body side is 1:1.1 to 1:6. The packaging bag according to any one of claims 1 to 6, characterized in that the passage is provided at the center in the direction in which the zipper portion extends. The packaging bag according to any one of claims 1 to 7, characterized in that the passages are spaced apart from one another. The packaging bag according to any one of claims 1 to 8, characterized in that both side portions of the passage connecting the end portion of the bag lower body portion side and the end portion of the bag upper body portion side are straight, curved, or have a shape that combines straight lines and curves. 10. The packaging bag according to claim 1, wherein the passage has a straight portion extending from the opening on the lower body side of the bag with the same opening width as the opening on the upper body side of the bag , and an enlarged portion whose opening diameter increases from the end of the straight portion toward the opening on the upper body side of the bag. The straight portion extends beyond the first portion of the zipper portion and/or the second portion of the zipper portion to the bag upper body portion side,
The packaging bag according to claim 10, wherein the enlarged portion is located closer to the bag upper body portion than the first portion of the zipper portion and/or the second portion of the zipper portion. The packaging bag according to any one of claims 1 to 11, characterized in that the bottom portion has a gusset portion so that the packaging bag can stand on its own.

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